Recent progress of HTS magnet using Bi-2223Ag-sheathed wire

We have succeeded in developing two types of refrigerator cooled High-Tc su perconducting magnets - a high magnetic field type and a large bore type. T he high magnetic field type has a room temperature bore of 50mm, an inner d iameter of 80 mm and an outer diameter of 300 mm, The coil height is 200mm, using 24 double pancakes. The magnet generated 7.1T over 24 hours and was excited at a rate of 7T/minute, This high ramp rate was ten times faster th an that of a refrigerator cooled magnet using metallic superconducting wire s. The large bore type magnet has a room temperature bore of 280mm, an inne r diameter of 400mm and an outer diameter of 520mm, The coil height is 18mm using 2 double pancakes. The magnet generated 0.17T and was excited at a r ate of 0.034T/s. These two types of HTS magnets, produced by using only Bi- 2223 Ag-sheathed tapes, have been continuously operated at 20K for practica l applications.